Liquid dispensing devices are used in various purposes for domestic, industrial and scientific environments. A common design employs a plunger in a barrel where the liquid is forced out of a nozzle connected to a plunger as the plunger is depressed. A recent development is disclosed in U.S. Pat. No. 5,050,782 in which the plunger is selectively limited in its depression thereby providing a predetermined amount of liquid. While this design is capable of delivering a measured dosage of liquid, the devise is not well suited for the delivery of pharmaceutical ingredients. This shortcoming is particularly apparent in the dosage of pharmaceutical ingredients which can not be sold without childproof protection. Those with skill in the art appreciate the need to provide accurate delivery of pharmaceutical ingredients while also preventing an accidental overdosing by the children who gain access to a dispenser.